1. Field of The Invention
This invention relates to roof tiles. More particularly, it refers to an insulating roof system for installation over an existing pitched roof.
2. Description of the Prior Art
Secondary roofing materials made from polystyrene and coated with a cement like layer have been well known in the roofing industry for their insulating qualities for at least twenty years. Unfortunately, such coated polystyrene tiles will often crack after a few years exposure to the elements and give the roof an unsightly appearance. In addition, roofing panels have previously been made from polystyrene or polyurethane overlapped with a metal sheet such as aluminum. See U.S. Pat. Nos. 3,875,715; 4,445,305 and 4,499,645. However, these prior art panels have been difficult to bond to a pitched roof without fear of wind damage. A roofing tile providing substantial insulation, ease of installation and strongly bonded to the roof to prevent wind driven damage is needed.